This application is a competitive renewal from the Alpert School of Medicine at Brown University for the NICHD Cooperative Multicenter Neonatal Research Network. The Neonatal Research Network has been in existence since 1986 and has the following goals: 1) to perform high quality, rigorous clinical trials for management and treatment of important morbidities that affect the outcome of term and preterm infants, 2) to ascertain temporal changes in morbidity and mortality for the highest risk infants, 3) to evaluate the epidemiology of specific morbidities using prospective observational cohort studies, 4) to evaluate new diagnostic tests that could not be done readily in a single center, and 5) to generate new hypotheses for investigation by analyzing morbidity, mortality and 18-22 month outcomes of survivors. The Brown site has been a member of the Network since 1991 and patients for Network studies are derived from a new, state of the art 80 bed Neonatal Intensive Care Unit (NICU) of Women and Infants Hospital of Rhode Island (WIH). WIH is a major teaching affiliate of the Alpert School of Medicine and is the only tertiary NICU in Southeastern New England. WIH has almost 9,000 deliveries per year (73% of the R.l. births) and coordinates a well regionalized perinatal care system which assures the care of all high risk infants in one facility. Comprehensive follow-up of infants from the NICU is conducted in the WIH Follow-up clinic. Adjoining WIH is Hasbro Children's Hospital which provides all specialized pediatric services. The Brown site has a well organized research team that includes Physicians with broad expertise in neonatal morbidities and multicenter studies, outstanding Research Nurses, and excellent follow-up to assess early childhood neurodevelopment. The Brown site has a track record of strong contributions to Network studies, minimal protocol deviations, accurate data acquisition and substantial scientific input to new protocol development. The Brown site is well positioned to continue to function as an outstanding Neonatal Research Network center and contribute to the overall goal of improving neonatal care and outcomes through rigorous research and evidence based medicine.